Bingham and Qin Zhu, lead author of the study and assistant professor at the University of Wyoming, Laramie, consider throwing and language in concert, because both require extremely well-coordinated timing and motor skills, which are facilitated by two uniquely developed brain structures -- the cerebellum and posterior parietal cortex.
"The idea here is that our speech and throwing capabilities came as a package," said Bingham, director of the Perception/Action Lab at IU. Language is special, and we acquire it very rapidly when young. Recent theories and evidence suggest that perceptual biases in auditory perception channel auditory development, so that we become attuned to the relevant acoustic units for speech. Our work on the size-weight illusion is now suggesting that a similar bias exists in object perception that corresponds to human readiness to acquire throwing skills."
Bingham and Zhu, who completed his doctorate in the Department of Kinesiology at IU's School of Health, Physical Education and Recreation, put their theory to the test, recruiting 12 adult men and women to perform various tests related to perception, the size-weight illusion and throwing prowess.
Another way of stating the size-weight illusion is that for someone to perceive that two objects -- one larger than the other -- weigh the same, the larger object must weigh significantly more than the smaller object. Their study findings show that skilled throwers use this illusion of 'equal felt' heaviness to select objects that they are able to throw to the farthest, maximum distance. This, says Bingham, suggests the phenomenon is not actually an illusion but instead a "highly useful and accurate perception."
Neanderthals, which co-existed with
|Contact: Geoffrey Bingham|